The invention relates to a system for recording and displaying machine fault histories, and more particularly, to recording and displaying in memory both machine fault data as well as the state of the machine at the time of the fault.
As reproduction machines such as copiers and printers become more complex and versatile in the jobs they can do, the interface between the machine and the service rep must necessarily be expanded if full and efficient trouble shooting of the machine is to be realized. A suitable interface must not only provide the controls, displays, and fault histories necessary to monitor and maintain the machine, but must do so in an efficient, relatively simple, and straightforward way.
Diagnostic methods often require that a service rep perform an analysis of the problem. For example, problems with paper movement in a machine can occur in different locations and occur because of various machine conditions or failure of various components. In the prior art, this analysis by the service representative has been assisted by recording fault histories in the machine control to be available for readout and analysis. For example, U.S. Pat. No. 5,023,817 discloses a method for recording and displaying in a finite buffer, called a last 50 fault list, machine faults as well as fault trends or near fault conditions. This data is helpful in diagnosing a machine. It is also known in the prior art, in addition to the last 50 fault list, to provide a much larger data log, known as an occurrence log, to record a variety of machine events.
A difficulty, however, with the prior art is that the occurrence log or buffer is finite and generally records event data on a first-in first-out basis. Therefore, event data is eventually lost as it gives way to more current data. Thus, crucial data such as the occurrence of a specific event or fault, and the events or faults surrounding it, may not be available to the service representative to aid in analysis and diagnostics. Often this lost information can be of significant value to aid in diagnosing and servicing a machine.
It is a feature of the present invention to overcome the above and other related problems and to make easier the diagnosis and servicing of the machine. An object of the present invention, therefore, is to provide a technique to capture the occurrence log related to a particular machine fault or event. Another object of the present invention is to be able to trigger the transfer of the occurrence log to a non-volatile or permanent memory in relation to a predetermined machine event or fault. Further advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.